Sickle cell disease (SCD) is caused by a genetic mutation in the hemoglobin gene which causes red blood cells to "sickle" under conditions of low oxygen. SCD affects 1:500 African-Americans and is also common in Hispanic-Americans. The median survival for patients with SCD is 42 years for males and 48 years for females. A team at UCLA is genetically modifying a patient’s own blood stem cells to produce a correct version of hemoglobin, the protein that is mutated in these patients, which causes abnormal sickle-like shaped red blood cells. These misshapen cells lead to dangerous blood clots, debilitating pain and even death. The genetically modified stem cells will be given back to the patient to create a new sickle cell-free blood supply.